THREE-DIMENSIONAL NONLINEAR DYNAMICS OF COLD ATOMS IN AN OPTICAL LATTICE AND ITS REALIZATIONS

摘要

We examine the coherent dynamics of cold atoms in a three-dimensional (3D) optical lattice (OL) without interference between counter-propagating laser beams. The dynamics is treated in the semiclassical approximation taking into account a coupling between the atom internal and external degrees of freedom. This coupling has been shown before to lead to either regular or chaotic motion for a single two-level atom in dependence on the values of control parameters, the detuning between the atomic transition and laser frequencies, and the atom recoil frequency. In this paper, we carry out numerical experiments on spreading of clouds with a large number of cold noninteracting atoms at different values of the detuning allowing one to compare the evolution of atomic clouds in regular and chaotic regimes of motion. We show that the distributions of atoms differ in those regimes providing a way to control atomic transport by varying the detuning. We propose experimental measurements able to distinguish between the regular and chaotic regimes of atom motion and to observe a signature of chaos with real cold atoms in 3D OLs.